*melanin: the pigment produced by your skin that gives it a tanned colour. 2. Take your time, and build your tan up slowly. Everyone reacts differently to the sun, but here are some guidelines to get you started: If tanning in the sun, start with only 15-20 minutes in the sun on your first session. In your following tanning sessions only increase your time by 5-10 minute increments, and monitor your skin regularly to make sure you arenât starting to go red and burn. If tanning on a sunbed, start with 2-3 minutes.
Over 2,000 years, many imperial dynasties and kingdoms built, rebuilt, and extended walls many times that subsequently eroded. The latest imperial construction was performed by the Ming Dynasty (1368â1644), and the length was then over 6,000 kilometers (3,700 miles). This is the wall often referred to when we talk about the Great Wall.
The Chinese rulers began construction of the canal about 2,400 years ago. The Chinese also started work on the Great Wall of China over 2,000 years ago. The Great Wall eventually stretched nearly 1,400 miles from the Yellow Sea westward. In some places, it stood 40 to 50 feet high. Its base was 15 to 30 feet thick.